Brockway Natural Tweed (1.43 TOG) with Cloud 9 Charleston 9 (2.5 TOG) gives a combined 2.93 in-situ TOG. Whether that passes the 2.5 TOG underfloor heating limit and what to do.

Updated 05 September 2026.

Combined TOG result

Brockway Natural Tweed and Cloud 9 Charleston 9: combined TOG for underfloor heating

The combined TOG for Brockway Natural Tweed over Cloud 9 Charleston 9, worked against the UHMA underfloor heating rule.

1.52.5
2.93TOG in situ
Fail · limit 2.5
Published TOG stack (carpet + underlay)
carpet 1.43
underlay 2.5
limit

Combined against the UHMA 2.5 TOG underfloor-heating limit. Under 1.5 also suits a low-temperature heat pump.

Carpet TOGUnderlay TOGPassMarginalFail
Combined in-situ TOG is 2.93, above the 2.5 TOG limit, so Brockway Natural Tweed with Cloud 9 Charleston 9 is not suitable for underfloor heating. Keep the carpet and switch to a low-TOG underlay.
The combined-TOG calculation
CarpetBrockway Natural Tweed (1.43 TOG)
UnderlayCloud 9 Charleston 9 (2.5 TOG)
Published sum3.93 TOG
UHMA in-situ correctionminus 1 TOG
Combined in-situ TOG2.93 TOG
Standard UFH limit2.5 TOG
Heat pump targetunder 1.5 TOG

Brockway Natural Tweed is rated 1.43 TOG and Cloud 9 Charleston 9 is rated 2.5 TOG. Laid together the combination is what the underfloor heating has to warm through.

The published TOG figures add to 3.93, and even after the UHMA 1 TOG in-situ correction the pair sits at 2.93 TOG, 0.43 TOG over the limit. The carpet is fine; the underlay is doing the damage. Keep Brockway Natural Tweed and drop to a low-TOG underlay such as Duralay Heatflow for Carpet (0.75 TOG) or Duralay Technics 5 (0.56 TOG), which brings the combined figure back into range.

The underlay to buy instead
Shop Duralay Heatflow for Carpet (0.75 TOG) on AmazonaffiliateFind Duralay Heatflow for Carpet (0.75 TOG) on eBayaffiliateShop Duralay Technics 5 (0.56 TOG) on AmazonaffiliateFind Duralay Technics 5 (0.56 TOG) on eBayaffiliate
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Questions and answers

Brockway Natural Tweed and Cloud 9 Charleston 9: combined TOG for underfloor heating?

Combined in-situ TOG is 2.93, above the 2.5 TOG limit, so Brockway Natural Tweed with Cloud 9 Charleston 9 is not suitable for underfloor heating. Keep the carpet and switch to a low-TOG underlay.